I love my Strikefire. I have had it for about 6 months now and have shot about 1000 rounds through my AR. I set it up at 100yds when I first bought the rifle, and checked the 0 last weekend. Still on. I'm not sure what everyone's complaint is about the on/off switch. I have never even come close to "accidentally" turning on the dot. In fact, I sometimes have to really press that sucker to get it to come on. I love the red/green switchability and the intensity adjustment, as it has given me a lot of flexibility in shooting outdoors in different light conditions (cloudy vs. sunny vs. low light, etc). As far as the dot looking like a "bunch of grapes", I just don't see it. It's not perfectly round, maybe more square shaped, but small and the lower the intensity level, the smaller it appears. And I'm not sure what the hell that guy was doing with his gun that he broke the mount! It's a huge, solid mount that you would have to beat someone with to break it. There is no way in hell he broke it shooting. If he did, he got a lemon. I do, however, agree with the doubler review. It's not much of an added value.
In any event, I can see one poster's point about saving your money for the optic you want. His wisdom is sage and you should probably listen to him and get a cheap iron rear sight that will get you shooting on paper for $30 and get the Aimpoint when you collect a few more paychecks. In the end you won't be saying to yourself, "man, I wish I had just waited and gotten the one red dot I really wanted, now I have this spare Vortex to get rid of." As for me, I never planned to get an Aimpoint (I wanted to build a sub $1000 fun AR) so the Vortex was the perfect choice for me.
YMMV,
Nuke